Prior art lighting domes, are known to those skilled in the art of photography. There are commercial domes for viewing semiconductor wafers that have a large hole in them for the lens to view through. For instance, a conventional dome reflector is typically a hollow hemispherical shell with a reflectively coated interior. Lights located along the interior rim of the shell reflect off the interior to illuminate an object to be viewed. For shiny spherical and convex objects, dome illuminations provide a somewhat diffuse and homogeneous light with less reflection.
Conventional optical systems use a lens with a front element whose size determines the aperture on the dome required to view the wafer. As this aperture size is increased the reflection of the lens in the image of the wafer makes a significant portion of the image unusable. To overcome this and other issues, U.S. Pat. No. 5,684,530 describes a second optical arrangement over the aperture in the dome to allow the illumination of the central spot with a second light source.
However, the disadvantages of this second optical arrangement include the following difficulties. The lighting in the central part through which the camera views the object is not truly multi-directional. The lighting for the central part is from a different light source so the colors and the intensities must be matched to that of the source for the dome making it difficult to use in practice. The height of the light source is increased. The beam-splitter through which the camera views the object can introduce changes to the light passing through it and obstruct the view of the object. What is needed is lighting dome technology that addresses the above-discussed issues in a cost-effective manner.
Meanwhile, the challenges of visual inspection or macro-inspection of semiconductor wafers an applet, a servlet, a source code, an object code, a shared library/dynamic load library and/or other sequence of instructions designed for execution on a computer or computer system).
The term substantially is intended to mean largely but not necessarily wholly that which is specified. The term approximately is intended to mean at least close to a given value (e.g., within 10% of). The term generally is intended to mean at least approaching a given state. The term coupled is intended to mean connected, although not necessarily directly, and not necessarily mechanically. The term proximate, as used herein, is intended to mean close, near adjacent and/or coincident; and includes spatial situations where specified functions and/or results (if any) can be carried out and/or achieved. The term distal, as used herein, is intended to mean far, away, spaced apart from and/or non-coincident, and includes spatial situation where specified functions and/or results (if any) can be carried out and/or achieved. The term deploying is intended to mean designing, building, shipping, installing and/or operating.
The terms first or one, and the phrases at least a first or at least one, are intended to mean the singular or the plural unless it is clear from the intrinsic text of this document that it is meant otherwise. The terms second or another, and the phrases at least a second or at least another, are intended to mean the singular or the plural unless it is clear from the intrinsic text of this document that it is meant otherwise. Unless expressly stated to the contrary in the intrinsic text of this document, the term or is intended to mean an inclusive or and not an exclusive or. Specifically, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). The terms a and/or an are employed for grammatical style and merely for convenience.
The term plurality is intended to mean two or more than two. The term any is intended to mean all applicable members of a set or at least a subset of all applicable members of the set. The term means, when followed by the term “for” is intended to mean hardware, firmware and/or software for achieving a result. The term step, when followed by the term “for” is intended to mean a (sub)method, (sub)process and/or (sub)routine for achieving the recited result. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. In case of conflict, the present specification, including definitions, will control. include the following issues. The produce can change from one batch to another, thereby changing the expectation of what a good wafer looks like. The product is highly reflective so it is difficult to illuminate without glares. A defect can be hard to define, especially when the failure mechanism is not known. These challenges make manual inspection of the wafers the industry default macro-inspection. But a disadvantage of this approach has been relatively high cost. What is needed is a wafer inspection solution that obviates the above-discussed issues in a cost-effective manner.